The nine-knot tailwind was not factored into the crew's landing calculations. During the descent, the final runway selection was not made until the aircraft was 8.5nautical miles from the airport. It is not known if the timing of this decision contributed to the omission of the tailwind during the calculation of landing performance. The tailwind had not been factored into the landing calculation, even though the captain asked the tower controller to repeat the surface wind on final approach. During the approach the tailwind made it difficult to maintain a normal descent profile. The rate of decent and airspeed were both higher than normal. The captain reduced the engine power to idle 16seconds prior to touchdown, likely because he recognised that the approach was in jeopardy because of excessive speed. The touchdown speed of the aircraft was 14to 24knots above the calculated VRef. The excess speed would have exacerbated the effect of the tailwind, resulting in a further increase in the stopping distance. The discrepancy between the stopping distance calculated by the engineering landing simulation (5940feet), and the actual stopping distance (6400-7100feet) may be due to factors such as flare technique, braking technique, and differences between the actual runway conditions and estimated runway conditions. The combination of the high threshold crossing height, excessive approach and touchdown speeds, and the extended touchdown point resulted in the aircraft overrunning the runway and striking the barricades. The approach was not a stable one, and a missed approach (go-around) would have been an appropriate course of action. Some of the FDR parameters were faulty, resulting in erroneous recordings and difficulty in interpreting actual aircraft performance.Analysis The nine-knot tailwind was not factored into the crew's landing calculations. During the descent, the final runway selection was not made until the aircraft was 8.5nautical miles from the airport. It is not known if the timing of this decision contributed to the omission of the tailwind during the calculation of landing performance. The tailwind had not been factored into the landing calculation, even though the captain asked the tower controller to repeat the surface wind on final approach. During the approach the tailwind made it difficult to maintain a normal descent profile. The rate of decent and airspeed were both higher than normal. The captain reduced the engine power to idle 16seconds prior to touchdown, likely because he recognised that the approach was in jeopardy because of excessive speed. The touchdown speed of the aircraft was 14to 24knots above the calculated VRef. The excess speed would have exacerbated the effect of the tailwind, resulting in a further increase in the stopping distance. The discrepancy between the stopping distance calculated by the engineering landing simulation (5940feet), and the actual stopping distance (6400-7100feet) may be due to factors such as flare technique, braking technique, and differences between the actual runway conditions and estimated runway conditions. The combination of the high threshold crossing height, excessive approach and touchdown speeds, and the extended touchdown point resulted in the aircraft overrunning the runway and striking the barricades. The approach was not a stable one, and a missed approach (go-around) would have been an appropriate course of action. Some of the FDR parameters were faulty, resulting in erroneous recordings and difficulty in interpreting actual aircraft performance. The crew did not factor in the nine-knot tailwind into the landing calculations. The captain did not initiate a missed approach when the aircraft was clearly not on a stable approach. The combination of the high threshold crossing height, excessive approach and touchdown speeds, and the extended touchdown point resulted in the aircraft overrunning the runway and striking the barricades.Findings as to Causes and Contributing Factors The crew did not factor in the nine-knot tailwind into the landing calculations. The captain did not initiate a missed approach when the aircraft was clearly not on a stable approach. The combination of the high threshold crossing height, excessive approach and touchdown speeds, and the extended touchdown point resulted in the aircraft overrunning the runway and striking the barricades. Several of the flight data recorder (FDR) parameters were faulty.Other Findings Several of the flight data recorder (FDR) parameters were faulty. The operator has taken the following safety actions: Immediate review of Flight Operations procedures for tail wind landing policy and clarification on wind additives as required. Flight crews have been alerted as to the precision required when determining maximum landing weight for given conditions at a specific airport. Increased training in Cockpit Resource Management (CRM) and implementation of the latest version of Threat and Error ManagementCRM (TEMCRM). This TEMCRM is currently taught during recurring ground training modules. Stressing the importance of performance analysis charts in training scenarios (simulators) and line checks. Reemphasizing the definitions of wet runway in the FOM. Informing flight followers to give consideration to wet runway and tail wind conditions when flight planning. Reviewing of NOTAMs and weather during every training event.Safety Action Taken The operator has taken the following safety actions: Immediate review of Flight Operations procedures for tail wind landing policy and clarification on wind additives as required. Flight crews have been alerted as to the precision required when determining maximum landing weight for given conditions at a specific airport. Increased training in Cockpit Resource Management (CRM) and implementation of the latest version of Threat and Error ManagementCRM (TEMCRM). This TEMCRM is currently taught during recurring ground training modules. Stressing the importance of performance analysis charts in training scenarios (simulators) and line checks. Reemphasizing the definitions of wet runway in the FOM. Informing flight followers to give consideration to wet runway and tail wind conditions when flight planning. Reviewing of NOTAMs and weather during every training event.